• Korean Journal of Food Science and Technology
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• v.21 no.3
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• pp.364-369
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• 1989

Experiments were carried out to investigate on the effect of cryoprotectants to the quality changes of pork and beef muscles during frozen storage . Beef and pork muscles were mixed with various cryoprotectants and stored at $-20^{\circ}C$ in a chest freezer for 12 weeks. Samples were analyzed for pH changes, TBA value, free atty acid contents, water and salt soluble protein extractability. The results obtained are summerized as follows. The pH value in all of cryoprotectants added samples were increased up to 0.25-0.5 as in non-treated samples . The TBA value, free fatty acid contents were increased with storage time as compared with the non-treated sample. Cryoprotectant effect on water soluble protein extractability was greater in pork than in beef muscle during frozen storage, especially in pork muscle treated CP-B, mixture of sorbitol, sucrose and sodium tripolyphosphate, as compared with non-treated sample. Cryoprotectant effect on salt soluble protein extractability during frozen storage was more pronounced in the beef muscle treated with CP-A which was mixture of sorbitol, mono sodium glutamate and sodium tripolyphosphate, and in the pork muscle treated with CP-B, mixture of sorbitol, sucrose and sodium tripolyphosphate than in the non-treated sample.

• Korean Journal of Food Science and Technology
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• v.21 no.4
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• pp.505-510
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• 1989

Red muscle and white muscle were separated from bovine, porcine and poultry skeletal muscles, respectively. Intramuscular lipids were extracted and fractionated to neutral-, glyco- and phospho-lipid by silica gel chromagraphy and then fatty acid composition were analyzed with gas chromatography. The results obtained were as follows; Total lipid content of red muscle was higher than that of white muscle in case of beef and chicken. In pork, however, total lipid content of white muscle was higher than red muscle The content ratio of neutral lipid to phospholipid revealed a number of distinctions between red and white muscle among animals. There were noteworthy differences in respect of polyunsaturated fatty acid. The intramuscular fat of pork had the higher content of highly polyunsaturated fatty acid such as arachidonic acid in contrast to beef.

• Food Science of Animal Resources
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• v.30 no.4
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• pp.626-633
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• 2010

This study examined the relationship between meat color and myoglobin content, and evaluated their influence on muscle fiber characteristics and overall pork quality. Four groups of pigs were classified by lightness (CIE $L^*$) and redness (CIE $a^*$): HH, high lightness and high redness; HL, high lightness and low redness; LH, low lightness and high redness; LL, low lightness and low redness. Myoglobin content ranged from 1.2 mg/g to 2.1 mg/g, and was highest in the LH group and lowest in the LL group (p<0.05). Myoglobin content correlated significantly with redness (CIE $a^*$) (r = 0.45, p<0.01). Fiber compositions of type I and IIA were closely related to lightness and redness. Pork with higher sizes of type IIA and IIB fibers had lower lightness and redness, respectively, which was tougher than the other pork. Pork having the highest lightness and lowest redness, often considered "pale", has higher values in drip loss than the other classes of pork tested.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.12
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• pp.1764-1769
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• 2000

The purpose of this experiment was to investigate the antioxidant effect of nitrite on total, neutral, and polar lipids and fatty acid composition in laboratory-cooked ground pork. Muscle samples (Biceps femoris) were analyzed using Iatroscan, gas chromatography, phosphorus content, and TBARS value. The total and neutral lipid contents of muscle were higher in nitrite-untreated meat (0 ppm) than in nitrite-treated meat (100 ppm) but the reverse was observed for polar lipid contents. The results for neutral lipids showed a similar trend when compared with total lipids. Polyunsaturated fatty acids contents of total, neutral and polar lipid in 100 ppm treated meat were higher than that of 0 ppm. The phosphorus content was higher in 100 ppm meat than in 0 ppm but the reverse was observed for TBARS value. These results showed that the addition of 100 ppm nitrite to ground pork resulted in a remarkable antioxidant effect during refrigeration storage.

• Journal of Food Hygiene and Safety
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• v.14 no.1
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• pp.27-33
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• 1999

Phytic acid, making up 1~5% of the composition of many plant seeds and cereals, is known to form iron-chelates and inhibit lipid peroxidation. Thiobarbituric acid reactive substances (TBARS), as an indication of lipid peroxidation, were measured in beef round, chicken breast, pork loin, and halibut muscle after the meats were stored for 0, 1, 3, 5, and 7 days at various temperatures [frozen (~2$0^{\circ}C$), refrigerator (4$^{\circ}C$), and room temperature ($25^{\circ}C$)]. Phytic acid effectively inhibited lipid peroxidation in beef round, chicken breast, halibut, and pork loin muscle (p<0.05). The inhibitory effect of phytic acid was dependent on concentration, storage time, and temperature. At frozen temperature, the inhibitory effect of phytic acid was minimal, whereas at room temperature, the inhibitory effect of phytic acid was maximal, probably due to the variation of the control TBARS values. At the concentration of 10 mM, phytic acid completely inhibited lipid peroxidation in all the muscle foods by maintaining TBARS values close to the level of the controls, regardless of storage time or temperature (p<0.05). The rate of lipid peroxidation was the highest in beef round muscle, although they had a close TBARS value at 0 day. Addition of phytic acid to lipid-containing foods such as meats, fish meal pastes, and canned seafoods may prevent lipid peroxidation, resulting in improvement of the sensory quality of many foods and prolonged shelf-life.

• Food Science and Biotechnology
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• v.14 no.5
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• pp.639-644
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• 2005

The aim of this study was to investigate the effect of the myosin light chain (MLC) isoforms on the muscle fiber characteristics and meat quality traits in porcine longissimus muscle. Pale, soft, exudative (PSE) samples had a lower content of essential light chain (ELC) 1S isoforms and a higher proportion of the fiber type IIB than the reddish-pink, firm, non-exudative (RFN) samples. These compositions suggest that the PSE pork has a higher glycolytic and a lower oxidative capacity than the RFN pork. Therefore, these characteristics of PSE pork might affect the metabolic rate and meat quality traits, including protein solubility. In addition, the indicator traits of the postmortem metabolic rate were related to the ELC 1F/3F ratio ($pH_{45\;min}$: r = -0.43, P < 0.001; R-value: r = 0.53, P < 0.001). These results suggest that the MLC isoform composition can affect the postmortem metabolic rate and meat quality traits.

• Food Science of Animal Resources
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• v.36 no.5
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• pp.583-593
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• 2016

The aim of this study was to investigate the effects of morphological characteristics of porcine muscle fibers on growth performance, muscle fiber characteristics, and pork quality taken from the longissimus dorsi muscle. A total of 239 crossbred pigs (164 castrated males and 75 females) were used in this study. Experimental pigs were categorized by the total number of muscle fiber (TNF: High and Low) and cross sectional area of muscle fiber (CSAF: Large, Middle, and Small). Their combinations were classified into six groups (High-Large, HL; High-Middle, HM; High-Small, HS; Low-Large, LL; Low-Middle, LM; Low-Small, LS). The TNF and CSAF were significantly (p<0.05) correlated with growth rate and carcass productivity, while the only of the type I number had no meaningful relationships excluding the correlation with loin area (p<0.001). The proportion of type I area was positively correlated with pH_{45 min} while the proportion of type IIB area was negatively correlated with pH_{45 min} and pH_{24 h} (p<0.05). Drip loss and protein denaturation had strong relationships with the proportion of type IIB number or area. The HL group exhibited the greatest growth performance. In addition, the HL group had significantly greater values in protein solubility than the other groups. In conclusion, this study suggest that high TNF combined to large CSAF improve the ultimate lean meat productivity and assure normal meat quality simultaneously with increased both proportion of number and area of type I, type IIA muscle fibers and lowered proportion of number and area of type IIB.

• Animal Bioscience
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• v.37 no.2
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• pp.284-294
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• 2024

Objective: Pork is an important source of animal protein in many countries. Subtle physiochemical changes occur during pork postmortem aging. The changes of apoptosis and autophagy in pork at 6 h to 72 h after slaughter were studied to provide evidence for pork quality. Methods: In this article, morphological changes of postmortem pork was observed through Hematoxylin-eosin staining, apoptotic nuclei were observed by TdT-mediated dUTP nick end labeling assay, protein related to apoptosis and autophagy expressions were tested by western blot and LC3 level were expressed according to immunofluorescence assay. Results: In this study, we found the occurrence of apoptosis in postmortem pork, and the process was characterized by nucleus condensation and fragmentation, formation of apoptotic bodies, increase in apoptosis-related Bax/Bcl-2 levels, and activation of caspases. Autophagy reached its peak between 24 and 48 h after slaughter, accompanied by the formation of autophagosomes on the cell membrane and expression of autophagy-related proteins beclin-1, P62, LC3-I, LC3-II, and ATG5. Conclusion: Obvious apoptosis was observed at 12 h and autophagy reached its peak at 48 h. The present work provides the evidence for the occurrence of apoptosis and autophagy during postmortem aging of pork. In conclusion, the apoptosis and autophagy of muscle cells discovered in this study have important implications for pork in the meat industry.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.10
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• pp.1529-1534
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• 2008

The aim of this study was directed at exploring the possible use of muscle fiber characteristics as new selection traits for improving both porcine lean meat production and quality. A total of 174 (114 Yorkshire, 30 Landrace, and 30 Meishan) pigs were used for this study, and lean meat production ability was estimated by backfat thickness and loin eye area. The Longissimus dorsi muscle was taken in order to measure meat quality and muscle fiber characteristics. Due to the high correlations between total muscle fiber number and most of the performance traits, all pigs were classified into three groups (low, intermediate, or high) by total muscle fiber number using cluster analysis. The high group had the highest loin eye area (p<0.001). The meat quality traits were within normal ranges as reddish pink, firm, and nonexudative (RFN) pork, but the groups classified as intermediate and high had relatively large drip loss percentages (p<0.05), produced more than twice the amount of pale, soft, and exudative (PSE) pork as compared to the low group. The group with a high total muscle fiber number was further classified, based on type 2b fiber percentage, into low or high groups by cluster analysis. The results showed that the low type 2b fiber group had good loin eye area (p<0.05), small drip loss (p<0.05), and did not produce PSE pork. For these reasons, a high total muscle fiber number, with a low percentage of type 2b fibers, may be suitable in selecting for improvements in both lean meat production and meat quality.

• Korean Journal of Veterinary Research
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• v.41 no.1
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• pp.13-19
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• 2001

A simple and rapid analytical method for the determination of tylosin in chicken, pork and muscle was established by High-Performance Liquid Chromatography(HPLC). Chicken, pork and beef muscle(5 g) were fortified by adding the $0.2{\mu}g/ml$ of standard tylosin and the drug was extracted from meats with 70% acetonitrile(ACN) and followed by liquid-liquid partition for clean-up procedure. Then $20{\mu}l$ portion of ACN elution was directly analyzed by HPLC with spectra 100 variable wavelength detector, and unfortified blank control were treated similarly. The average recovery rate of tylosin added to chicken, pork and beef muscle were $83{\pm}2.3$, $96{\pm}3.3$ and $92{\pm}1.6$(%) at the level 0.2 ppm, respectively. No tylosin residues in marketing meats. These results suggested that HPLC methodology could be acceptable for the extraction, determination and screening of tylosin residues in edible meats.